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authorSean Christopherson <sean.j.christopherson@intel.com>2018-04-30 10:01:06 -0700
committerPaolo Bonzini <pbonzini@redhat.com>2018-05-11 11:21:13 +0200
commit64f7a11586ab9262f00b8b6eceef6d8154921bd8 (patch)
treebd19f53cf661297dacc895066697f26aec342b94 /arch
parentc19986fea873f3c745122bf79013a872a190f212 (diff)
downloadlinux-64f7a11586ab9262f00b8b6eceef6d8154921bd8.tar.bz2
KVM: vmx: update sec exec controls for UMIP iff emulating UMIP
Update SECONDARY_EXEC_DESC for UMIP emulation if and only UMIP is actually being emulated. Skipping the VMCS update eliminates unnecessary VMREAD/VMWRITE when UMIP is supported in hardware, and on platforms that don't have SECONDARY_VM_EXEC_CONTROL. The latter case resolves a bug where KVM would fill the kernel log with warnings due to failed VMWRITEs on older platforms. Fixes: 0367f205a3b7 ("KVM: vmx: add support for emulating UMIP") Cc: stable@vger.kernel.org #4.16 Reported-by: Paolo Zeppegno <pzeppegno@gmail.com> Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Suggested-by: Radim KrÄmář <rkrcmar@redhat.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kvm/vmx.c28
1 files changed, 15 insertions, 13 deletions
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index c7668806163f..3f1696570b41 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1494,6 +1494,12 @@ static inline bool cpu_has_vmx_vmfunc(void)
SECONDARY_EXEC_ENABLE_VMFUNC;
}
+static bool vmx_umip_emulated(void)
+{
+ return vmcs_config.cpu_based_2nd_exec_ctrl &
+ SECONDARY_EXEC_DESC;
+}
+
static inline bool report_flexpriority(void)
{
return flexpriority_enabled;
@@ -4761,14 +4767,16 @@ static int vmx_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
else
hw_cr4 |= KVM_PMODE_VM_CR4_ALWAYS_ON;
- if ((cr4 & X86_CR4_UMIP) && !boot_cpu_has(X86_FEATURE_UMIP)) {
- vmcs_set_bits(SECONDARY_VM_EXEC_CONTROL,
- SECONDARY_EXEC_DESC);
- hw_cr4 &= ~X86_CR4_UMIP;
- } else if (!is_guest_mode(vcpu) ||
- !nested_cpu_has2(get_vmcs12(vcpu), SECONDARY_EXEC_DESC))
- vmcs_clear_bits(SECONDARY_VM_EXEC_CONTROL,
+ if (!boot_cpu_has(X86_FEATURE_UMIP) && vmx_umip_emulated()) {
+ if (cr4 & X86_CR4_UMIP) {
+ vmcs_set_bits(SECONDARY_VM_EXEC_CONTROL,
SECONDARY_EXEC_DESC);
+ hw_cr4 &= ~X86_CR4_UMIP;
+ } else if (!is_guest_mode(vcpu) ||
+ !nested_cpu_has2(get_vmcs12(vcpu), SECONDARY_EXEC_DESC))
+ vmcs_clear_bits(SECONDARY_VM_EXEC_CONTROL,
+ SECONDARY_EXEC_DESC);
+ }
if (cr4 & X86_CR4_VMXE) {
/*
@@ -9497,12 +9505,6 @@ static bool vmx_xsaves_supported(void)
SECONDARY_EXEC_XSAVES;
}
-static bool vmx_umip_emulated(void)
-{
- return vmcs_config.cpu_based_2nd_exec_ctrl &
- SECONDARY_EXEC_DESC;
-}
-
static void vmx_recover_nmi_blocking(struct vcpu_vmx *vmx)
{
u32 exit_intr_info;